Loss of leg coordination while running as a task-specific focal dystonia distinct from runner's dystonia
An executive summary of findings on loss of leg coordination while running
Loss of leg coordination while running is the working term for a rare neurological problem that occurs in long distance runners. It is characterized by a gradually increasing sensation of tightness, weakness, and poor coordination in the muscles of one leg that occurs only while running—stopping to walk or stand still all but eliminates the symptoms. Runners with loss of leg coordination cannot point to a specific area of pain; rather, there is a more general feeling of tightness, vague aching, and an overwhelming sense of something being "off" with the functioning of the affected leg when they run. Further, classic signs of neurological injury, like numbness, shooting pain, or a "pins and needles" sensation, are absent.
These symptoms are also highly specific to running. Other activities, even cyclical and highly aerobically demanding ones like using an elliptical or riding a bike, do not reliably recreate the symptoms. The loss of coordination sensation is typically localized to the muscles which are the prime movers of the legs: the calves, the hamstrings, the quadriceps, and the gluteal muscles. Despite the weak, uncoordinated sensation while running, absolute muscular strength is normal.
In most cases, running longer, faster, and on flat surfaces exacerbates the problem. Some runners find they lose coordination with any kind of running, but most are able to run at an easy pace on rough terrain (e.g. on trails or over cross-country). Short intervals of fast running are not usually a problem, but longer intervals at fast speeds and especially fast continuous runs and races bring on loss of leg coordination more rapidly. Ceasing a run makes the loss of coordination sensation go away almost immediately, but some lower leg muscular tightness can persist for a few days after a particularly bad episode.
Runners with loss of leg coordination often present with secondary injuries and muscular tightness or weakness as a result of continuing to run with abnormal biomechanics. Clinical examination and diagnostic testing (straight leg raise test, nerve conduction, MRI, etc.) are typically unremarkable or uncover common conditions that are often asymptomatic, e.g. spinal disc herniation.
Loss of leg coordination tends to occur in very experienced, high-mileage distance runners who train and compete at a high level. An informal survey of sixteen distance runners with self-reported loss of leg coordination found a median age of onset of 22 years and median duration of four years at the time of the survey.
Managing loss of leg coordination is challenging. The symptoms cannot be easily ascribed to a conventional diagnosis, and working with a physical therapist to address strength and flexibility deficiencies usually results in only minor improvements. Among sixteen distance runners with self-reported loss of leg coordination, only two are able to train and compete at their previous level with no restrictions. A few others still train and compete at a high level, but with some restrictions. Most, however, cannot train or compete at nearly the same level as before the onset of loss of leg coordination.
The symptoms of loss of leg coordination while running are similar to task-specific focal dystonia of the lower limb (a condition termed "runner's dystonia" in some medical literature), but there are notable differences between loss of leg coordination while running and cases of runner's dystonia described in the literature.
The prognosis of runner's dystonia is very poor—of nineteen adequately-described cases in the literature, dystonic movements spread to activities beyond running and eventually led to significant problems with walking in all but three cases. In contrast, none of the sixteen runners with loss of leg coordination had significant gait impairments while walking. Many runners with loss of leg coordination have symptoms that have been essentially stable or marginally improving for several years, as opposed to the nearly-inevitable spread of dystonic movements to other activities reported in runner's dystonia.
The most common location of complaints also differs between runner's dystonia and loss of leg coordination. Fifteen of nineteen literature cases of runner's dystonia involved the muscles of the foot and ankle—ankle inversion or eversion and toe clawing were the most common gait abnormalities. In the case of loss of leg coordination, only four of sixteen cases involved the foot and ankle. The most common complaints with loss of leg coordination involve the muscles of the hips and thigh: hip flexion, hip rotation, and knee extension. Runners with loss of leg coordination sometimes report that their foot "splays" out upon impact, landing rotated and everted, but often this appears to be rooted in hip external rotation during the swing phase.
Patients with runner's dystonia complain of sustained contractions of the smaller muscles responsible for fine motor control, as is the case with better-known cases of focal dystonia (e.g. musician's dystonia, writer's cramp). Loss of leg coordination instead appears to involve a slight but perceptible "misfiring" of the prime movers of the leg as opposed to sustained contraction.
A case study of a runner with symptoms typical of loss of leg coordination, as opposed to runner's dystonia, has yet to be published in the medical literature. I encourage any physical therapist or doctor who is working with a patient with these symptoms to do so; it may spur the publication of additional case studies or series of runners with similar problems, some of whom may have been able to make improvements or a full recovery.
Treatments for runner's dystonia described in the medical literature are not promising. Strategies usually revolve around antiparkinsonian or anticonvulsant drugs and botulinum toxin, but results are very poor. No literature-described cases of runner's dystonia have made a full return to sport.
From the anecdotal experience of a number of informal survey respondants who have either fully overcome or successfully managed their loss of leg coordination and continued to run at a high level, there seem to be three strategies associated with a better outcome. First, these runners avoid any type of training that triggers loss of leg coordination. They do this by modifying their training schedule, changing their race distance of choice, and stopping workouts once loss of coordination occurs. Second, some runners reported success after taking an extended break from running and gradually reintroducing running, similar to how one might return after a major running injury like a stress fracture. In some cases, this was a necessary result of surgery (labral tear with FAI in two cases, lumbar decompression in another); in others it was voluntary. Third, every runner who has made significant improvements or made a full recovery has focused on improving strength and flexibility of the hip and thigh muscles over the course of several months, either through physical therapy-style strength exercises, weight lifting, or both.
For runners with loss of leg coordination, the initial goal should be management. Through improving strength and flexibility in the hips and thigh, modifying training to avoid triggering loss of leg coordination, and sometimes an extended break from running, some runners are able to return to training and competition at a high level with only minimal problems from loss of leg coordination. Two runners are known to have made a full recovery, returning to training and competition with no restrictions, and a third appears to be symptom-free but chooses to only run a few times per week. It is not clear what allowed these runners to make a full recovery.
Though the problem appears to be rooted in faulty movement patterns in the brain, this does not preclude other musculoskeletal injuries or weaknesses from contributing to the problem. A number of runners with loss of leg coordination reported also having other injuries; in a few cases, treating these led to improvement or recovery. All runners who have loss of leg coordination should be screened for other injuries and neurological problems as well.
Future directions for research should focus on developing neuromuscular reeducation programs to address the root cause of loss of leg coordination. The primary goal should be to restore the proper "image" of running in the brain. Researchers and therapists should consider looking to programs used to successfully treat task-specific focal dystonia in the hand and wrist as a starting point when attempting to create programs for runners.
References: All known cases of runner's dystonia in the medical literature
Note that some of these papers present non-running-related cases of lower limb focal dystonia as well.
Wu and Jankovic: 5 cases
Wu, L. J. C.; Jankovic, J., Runner’s Dystonia. Journal of the Neruological Sciences 2006, 251 (1-2), 73-76.
Leveille and Clement: 2 cases
Leville, L. A.; Clement, D. B., Case Report: Action-Induced Focal Dystonia in Long Distance Runners. Clinical Journal of Sports Medicine 2008, 18, 467-468.
Ramdhani and Frucht: 3 cases
Ramdhani, R. A.; Frucht, S. J., Adult-onset Idiopathic Focal Lower Extremity Dystonia: A Rare Task-Specific Dystonia. Tremor and Other Hyperkinetic Movements 2013.
Rana and Boke: 1 case
Rana, A. Q.; Boke, B. N., Difference of Foot Posture in Two Cases of Exercise-Induced Foot Dystonia. European Neurology 2013, 69 (2), 65-66.
Chang and Josephs: 3 cases
Chang, F. C. F.; Josephs, K. A., Levodopa Responsiveness in Adult-onset Lower Limb Dystonia is Associated with the Development of Parkinson’s Disease. Tremor and Other Hyperkinetic Movements 2013.
McClinton and Heiderscheit: 1 case
McClinton, S.; Heiderscheit, B. C., Diagnosis of Primary Task-Specific Lower Extremity Dystonia in a Runner. Journal of Orthopaedic & Sports Physical Therapy 2012, 42 (8), 688-697.
Katz et al.: 4 cases
Katz, M.; Byl, N. N.; San Luciano, M.; Ostrem, J. L., Focal task-specific lower extremity dystonia associated with intense repetitive exercise: A case series. Parkinsonism & Related Disorders 2013, 19 (11), 1033-1038.
Schneider et al.: 1 case
Schneider, S. A.; Edwards, M. J.; Grill, S. E.; Goldstein, S.; Kanchana, S.; Quinn, N. P.; Bhatia, K. P.; Hallett, M.; Reich, S. G., Adult-onset primary lower limb dystonia. Movement Disorders 2006, 21 (6), 767-771.
Bozi and Bhatia: 2 cases
Bozi, M.; Bhatia, K. P., Paroxysmal exercise-induced dystonia as a presenting feature of young-onset Parkinson's disease. Movement Disorders 2003, 18 (12), 1545-1547.
This executive summary and the accompanying 21,000 word full article were the culmination of five years of research, nineteen months of writing, and considerable emotional investment. I have published it free for anyone to read and distribute because I don't believe in restricting access to this kind of information. I am a freelance writer and part-time high school coach, not a professional scholar, so if you have made it all the way down here and found this article helpful, consider donating a few dollars to support my work.